Staining techniques
Microscopy and slide preparation · Biology
Study notes
Gram staining (1884) still decides treatment — purple cocci = Gram-positive (penicillin works), pink rods = Gram-negative; your throat swab's fate in one stain. Pap smears (cervical cancer screening) are staining-based diagnosis — cells' colours flag cancer. Forensic labs stain blood traces with luminol-adjacent chemistry — invisible evidence made visible. Overstaining hides everything — timing is the skill.